package org.bouncycastle.asn1.x509;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DEREncodable;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERString;
import org.bouncycastle.asn1.DERTaggedObject;

/**
 * Implementation of the RoleSyntax object as specified by the RFC3281.
 * 
 * <pre>
 * RoleSyntax ::= SEQUENCE {
 *                 roleAuthority  [0] GeneralNames OPTIONAL,
 *                 roleName       [1] GeneralName
 *           }
 * </pre>
 */
public class RoleSyntax extends ASN1Encodable {
    private GeneralNames roleAuthority;
    private GeneralName roleName;

    /**
     * RoleSyntax factory method.
     * 
     * @param obj
     *            the object used to construct an instance of <code>
     * RoleSyntax</code>. It must be an instance of <code>RoleSyntax
     * </code> or <code>ASN1Sequence</code>.
     * @return the instance of <code>RoleSyntax</code> built from the supplied object.
     * @throws java.lang.IllegalArgumentException
     *             if the object passed to the factory is not an instance of <code>RoleSyntax</code> or <code>ASN1Sequence</code>.
     */
    public static RoleSyntax getInstance(Object obj) {

        if (obj == null || obj instanceof RoleSyntax) {
            return (RoleSyntax) obj;
        } else if (obj instanceof ASN1Sequence) {
            return new RoleSyntax((ASN1Sequence) obj);
        }
        throw new IllegalArgumentException("Unknown object in RoleSyntax factory.");
    }

    /**
     * Constructor.
     * 
     * @param roleAuthority
     *            the role authority of this RoleSyntax.
     * @param roleName
     *            the role name of this RoleSyntax.
     */
    public RoleSyntax(GeneralNames roleAuthority, GeneralName roleName) {
        if (roleName == null || roleName.getTagNo() != GeneralName.uniformResourceIdentifier
                || ((DERString) roleName.getName()).getString().equals("")) {
            throw new IllegalArgumentException("the role name MUST be non empty and MUST " + "use the URI option of GeneralName");
        }
        this.roleAuthority = roleAuthority;
        this.roleName = roleName;
    }

    /**
     * Constructor. Invoking this constructor is the same as invoking <code>new RoleSyntax(null, roleName)</code>.
     * 
     * @param roleName
     *            the role name of this RoleSyntax.
     */
    public RoleSyntax(GeneralName roleName) {
        this(null, roleName);
    }

    /**
     * Utility constructor. Takes a <code>String</code> argument representing the role name, builds a <code>GeneralName</code> to hold the role name
     * and calls the constructor that takes a <code>GeneralName</code>.
     * 
     * @param roleName
     */
    public RoleSyntax(String roleName) {
        this(new GeneralName(GeneralName.uniformResourceIdentifier, (roleName == null) ? "" : roleName));
    }

    /**
     * Constructor that builds an instance of <code>RoleSyntax</code> by extracting the encoded elements from the <code>ASN1Sequence</code> object
     * supplied.
     * 
     * @param seq
     *            an instance of <code>ASN1Sequence</code> that holds the encoded elements used to build this <code>RoleSyntax</code>.
     */
    public RoleSyntax(ASN1Sequence seq) {
        if (seq.size() < 1 || seq.size() > 2) {
            throw new IllegalArgumentException("Bad sequence size: " + seq.size());
        }

        for (int i = 0; i != seq.size(); i++) {
            ASN1TaggedObject taggedObject = ASN1TaggedObject.getInstance(seq.getObjectAt(i));
            switch (taggedObject.getTagNo()) {
                case 0:
                    roleAuthority = GeneralNames.getInstance(taggedObject, false);
                    break;
                case 1:
                    roleName = GeneralName.getInstance(taggedObject, false);
                    break;
                default:
                    throw new IllegalArgumentException("Unknown tag in RoleSyntax");
            }
        }
    }

    /**
     * Gets the role authority of this RoleSyntax.
     * 
     * @return an instance of <code>GeneralNames</code> holding the role authority of this RoleSyntax.
     */
    public GeneralNames getRoleAuthority() {
        return this.roleAuthority;
    }

    /**
     * Gets the role name of this RoleSyntax.
     * 
     * @return an instance of <code>GeneralName</code> holding the role name of this RoleSyntax.
     */
    public GeneralName getRoleName() {
        return this.roleName;
    }

    /**
     * Gets the role name as a <code>java.lang.String</code> object.
     * 
     * @return the role name of this RoleSyntax represented as a <code>java.lang.String</code> object.
     */
    public String getRoleNameAsString() {
        DERString str = (DERString) this.roleName.getName();

        return str.getString();
    }

    /**
     * Gets the role authority as a <code>String[]</code> object.
     * 
     * @return the role authority of this RoleSyntax represented as a <code>String[]</code> array.
     */
    public String[] getRoleAuthorityAsString() {
        if (roleAuthority == null) {
            return new String[0];
        }

        GeneralName[] names = roleAuthority.getNames();
        String[] namesString = new String[names.length];
        for (int i = 0; i < names.length; i++) {
            DEREncodable value = names[i].getName();
            if (value instanceof DERString) {
                namesString[i] = ((DERString) value).getString();
            } else {
                namesString[i] = value.toString();
            }
        }
        return namesString;
    }

    /**
     * Implementation of the method <code>toASN1Object</code> as required by the superclass <code>ASN1Encodable</code>.
     * 
     * <pre>
     * RoleSyntax ::= SEQUENCE {
     *                 roleAuthority  [0] GeneralNames OPTIONAL,
     *                 roleName       [1] GeneralName
     *           }
     * </pre>
     */
    public DERObject toASN1Object() {
        ASN1EncodableVector v = new ASN1EncodableVector();
        if (this.roleAuthority != null) {
            v.add(new DERTaggedObject(false, 0, roleAuthority));
        }
        v.add(new DERTaggedObject(false, 1, roleName));

        return new DERSequence(v);
    }

    public String toString() {
        StringBuffer buff = new StringBuffer("Name: " + this.getRoleNameAsString() + " - Auth: ");
        if (this.roleAuthority == null || roleAuthority.getNames().length == 0) {
            buff.append("N/A");
        } else {
            String[] names = this.getRoleAuthorityAsString();
            buff.append('[').append(names[0]);
            for (int i = 1; i < names.length; i++) {
                buff.append(", ").append(names[i]);
            }
            buff.append(']');
        }
        return buff.toString();
    }
}
